A local girl in Nagoya — we do not need a tourist eSIM ourselves. We just watch every friend who visits get this wrong.
💴 Cost: unlimited data for a week, about $27 — pocket WiFi is roughly double
📍 Where: online before departure, not at the airport
😰 Difficulty: low — but one step must happen while you still have WiFi
1. Buy and install it at home, on your own WiFi. That is the whole trick
2. Unlimited data: ~$11.50 for 3 days · ~$27 for a week · ~$69 for a month
3. Pocket WiFi costs about double, and is a device to charge and return
4. Phone must be unlocked and eSIM-capable — most since 2020 are
5. Landed with nothing? Airport counters fix it, at a price
Japan has almost no useful free public WiFi. Between the airport and your hotel — the platform where you check the line, the corner where you need the map — you are on your own.
An eSIM is a SIM with no card: buy online, scan a QR, and your phone carries a Japanese data line alongside your usual number. It needs a phone that is carrier-unlocked and eSIM-capable — iPhone XS or newer, most Android flagships since 2020. Bought on a carrier payment plan? Check it is unlocked first. That is the most common failure.
What it costs
- 3 days $11.50 · 5 days $17 · 7 days $27 · 10 days $34.50 · 15 days $48 · 30 days $69 — unlimited data, July 2026
- Pocket WiFi for the same trips: about $51 for 5 days, $123 for a month
- Buy slightly longer than your trip. The 7-to-10-day gap is small, and a plan dying on your last morning is a miserable finish
Those are Airalo prices, which is what we hand to visiting friends: it covers Japan properly, the app is in English, and you can top up mid-trip without buying a second plan. Ubigi is the sensible alternative and occasionally cheaper on longer stays — check both for your exact number of days.
The step everyone gets wrong
Installing an eSIM requires an internet connection. Wait until you land, and you need WiFi to install the thing that gives you WiFi.
- At home: buy it, scan the QR, install the profile, leave the line off
- After landing: switch the line on, enable data roaming for it. Online before immigration
Most plans only count days from the first connection in Japan, so installing early costs nothing.
When pocket WiFi wins instead
- A group. One router covers four people; four eSIMs cost four times one
- A laptop. Tethering works but kills the phone by mid-afternoon
- A locked or pre-2020 phone. Then the decision is made for you
Landed with nothing? Every major arrivals hall has SIM counters past customs. Staff speak enough English and set the phone up in front of you. You will pay more than online.
TSŪ INFORMATIONwhat Japanese connoisseurs know
Japan runs on three networks — docomo, au and SoftBank — and every tourist eSIM is resold capacity on one of them. In the cities it makes no difference. It matters the moment you leave them: docomo reaches furthest into mountains and rural coast, which is exactly where you will be for Kumano Kodo, the Japan Alps or the smaller islands. City trip, take the cheapest. Outside the Tokyo–Kyoto–Osaka corridor, check which network the plan rides on — the listing says, in small type.
Honest notes
- “Unlimited” usually is not, quite. Most plans slow after a daily threshold. Maps and messaging, you will never notice. Streaming all day, you will
- No phone calls. A data-only eSIM cannot ring a restaurant that takes reservations by phone
• Install before you fly, on home WiFi. The only step that really matters
• ~$11.50 / 3 days · ~$27 / week · ~$69 / month, unlimited
• Pocket WiFi is about double — worth it only for groups or laptops
• Phone must be unlocked and eSIM-capable
• Going rural? Check for docomo, au or SoftBank
• Prices checked July 2026 · we live here, so we do not use these ourselves
More from us: this is step one of the full order of preparation. Once online, you will want how to order food without Japanese.